Anne Lyle
Fantastical historian
Does the instinct, if it exists, arise from the physique, or is it the opposite?
Not physique, but hormones. Hormones have a huge effect on our behaviour, and of course the two sexes have different hormone balances. For example, it's been shown that women are more attracted to hunky, macho men in the middle of their menstrual cycle, when they're fertile!
It seems to me, that if a person was trained to be a smithy, or a physicist, he should not prefer being a miner or a historian.
Why? Plenty of people, male and female, get pushed into careers they're not interested in by well-meaning parents. Fiction is rife with this theme.
And that's "smith", by the way. "Smithy" is the place where a smith works
Here I go, putting my head on the block, there are roles for which men are better equipped than women, just as the role of child bearing & rearing is especially suited to women.
Only a few roles are strongly reliant on male or female physique. Men naturally have more upper body strength, so any job that relies on a lot of heavy lifting or similar is going to be easier for a man - but not impossible for a woman (provided she isn't too petite). When it comes to mental aptitudes, there are some skills that are more common in men than in women, and vice versa, but there is a great deal of overlap.
Men and women are individuals, not two mutually exclusive groups. Some men enjoy working with children (and not for pervy reasons!), some women like me would rather work with computers any day of the week, thanks.